1. Field of the Invention
The present invention relates to a sheet treating apparatus for subjecting a sheet to treatment.
2. Related Background Art
In recent years, a sheet treating apparatus has been widely used as its advantage of extremely improving handling property of a sheet was recognized. The sheet treating apparatus subjects a sheet to at least one of sheet aligning treatment, sheet punching treatment, sheet binding treatment, sheet folding treatment, and the like.
A conventional sheet treating apparatus is a so-called “finisher”, which is connected to, for example, an image forming apparatus and subjects a sheet, on which an image is formed by the image forming apparatus, to the above-mentioned treatment. Examples of the image forming apparatus include a copying machine, a printer, a facsimile, and a multi-function apparatus thereof.
By the way, in the case in which a sheet treating apparatus is connected to, for example, an image forming apparatus and used, it is not always necessary to subject all sheets, on which images are formed by the image forming apparatus, to post-treatment.
However, conventionally, all the sheets having images formed thereon are transported to a sheet stacking portion by a driving force of a transporting roller or the like in the sheet treating apparatus, so that electric power is always consumed even if the sheets are not subjected to post-treatment.
In addition, in a structure in which all sheets pass through a sheet treating portion, an initialization operation of the sheet treating portion is performed or each transporting roller is rotated in the same manner as subjecting the sheets to post-treatment. Consequently, the conventional sheet treating apparatus wastes electric power. Moreover, if a sheet which is not required to be subjected to treatment is caused to pass through the sheet treating portion, the sheet may be smeared.
Further, in the conventional sheet treating apparatus, even a sheet which is not required to be subjected to the post-treatment passes through the sheet treating portion. Accordingly, components of the sheet treating portion operate unnecessarily. As a result, a useful life of the components is reduced. In addition, unnecessary operation results in increase of causes of failure.